Assertion:- Boric acid exist in solid state.
Reason:- H-Bond present in between two boric acid molecule.

Options

A. If both Assertion `&` Reason are True `&` the Reason is a correct explanation of the Assertion.
B. If both Assertion `&` Reason are True but Reason is not a correct explanation of the Assertion.
C. If Assertion is True but the Reason is False.
D. If both Assertion `&` Reason are False.

Answer

To solve the assertion-reason question regarding boric acid, we will analyze both the assertion and the reason step by step.

### Step-by-Step Solution:

1. **Understanding the Assertion**:
- The assertion states that "Boric acid exists in solid state."
- Boric acid (H₃BO₃) is indeed known to exist in solid form, particularly in its crystalline structure.

**Hint**: Remember that many acids can exist in solid form, especially when they have strong intermolecular forces.

2. **Analyzing the Structure of Boric Acid**:
- Boric acid has a molecular formula of H₃BO₃. Its structure consists of a boron atom bonded to three hydroxyl (–OH) groups.
- The arrangement allows for the formation of hydrogen bonds between the molecules.

**Hint**: Visualize the molecular structure and how the hydroxyl groups can interact with each other.

3. **Understanding the Reason**:
- The reason states that "H-Bond is present between two boric acid molecules."
- Hydrogen bonding occurs due to the attraction between the hydrogen atom of one hydroxyl group and the oxygen atom of another hydroxyl group in a neighboring boric acid molecule.

**Hint**: Consider how hydrogen bonds form and the role of electronegative atoms like oxygen in this process.

4. **Connecting Assertion and Reason**:
- The extensive hydrogen bonding between boric acid molecules leads to increased intermolecular forces of attraction.
- This strong intermolecular attraction is what allows boric acid to exist in a solid state.

**Hint**: Think about how stronger intermolecular forces can lead to a substance being solid at room temperature.

5. **Conclusion**:
- Both the assertion and the reason are true.
- The reason provided is a correct explanation for the assertion because the presence of hydrogen bonds is responsible for the solid state of boric acid.

### Final Answer:
Both the assertion and reason are true, and the reason is the correct explanation of the assertion.